1. Technical Field
This invention is related to computer peripheral equipment and more particularly to hand held portable computer equipment
2. Background Information
Prior art for single hand keyboards represents multiple attempts to invent alternative devices for the QWERTY keyboard for data entry. Perhaps the most important data point is that almost none of the inventions for one hand data entry has made it into a commercial product. The de facto standard input device for all computer systems, is the QWERTY arrangement of one key for one character data input. A commercial product that provides an alternative to QWERTY data entry in a pocket sized device is the "Agenda" made by Microwriter Inc. of London Eng. The "Agenda" uses only seven keys for data entry, five primary keys and two shift keys, and by pressing various combinations of keys up to a maximum of five keys at a time, all the characters of a conventional keyboard can be generated. The "Agenda" has failed to generate a profitable business, however, and it has been removed from the market. Thus, there has been no real progress to replace the QWERTY keyboard except in severely limited applications where the QWERTY arrangement simply won't work, like, for example, specialized chord key boards for people with only one arm or joy stick operated devices which have been devised for the severely handicapped.
There is extensive prior art in the area of single hand data input devices. For example Siebel et. al. in 1962 in U.S. Pat. No. 3,022,878 described an invention of a "man machine communication device that surrounds the hand and is remote from the controlled machine . . . to provide a keyboard into which the hand is inserted . . . " This device allowed for a large number of possible input signals with a single hand and allowed relatively "free movement of the hand" while data is being entered.
In 1983, Grimes was issued U.S. Pat. No. 4,414,537 for a "man machine interface . . . for translating discrete hand positions into electrical signals representing alpha-numeric characters. The interface comprises a glove . . . ". Similarly, in 1985 Kroczynski was issued U.S. Pat. No. 4,517,424 in which the functional elements of a data glove were incorporated into a device which "engages the hand . . . and maintains same in a fixed position while permitting movement of the fingers." Some earlier examples of related devices are a finger tip actuated solenoid device for the handicapped described by Karafian in 1967 in U.S. Pat. No. 3,507,376; a one handed code registration device described by Laenger in 1976 in U.S. Pat. No. 4,074,444; and also in 1976 Salmon described a one hand communication device for the dumb in U.S. Pat. No. 4,075,621.
In 1974, Hilborn, in a patent issued to the U.S. Government in U.S. Pat. No. 3,833,765 describes a pocket sized typewriter that uses sequential keying to uniquely define each character. This sequential keying of data, where multiple keys are sequentially struck and released, should be distinguished from the chording type of input, "Microwriting", described by Endfield. In "Microwriting" specific keys are pressed in any order and a character is recorded only when all keys are released.
The characteristic of "Microwriting" that allows keys to be struck in any order and to register a character only after all keys have been released is part of the foundation for the present invention. There have been other devices which are superficially similar in appearance to the present device but they operate in an entirely different way and if they were applied to "Microwriting" they would not work.
For example in 1988, U.S. Pat. No. 4,791,408 was issued to Heusinkveld in which he described a "data entry device having five keys, not in one plane, (which) is held in and operated by one hand. Each key has two `on` positions and one `off` position." The user of Heusinkveld's device must keep their fingers on the keys of his device at all times and although he uses discrete chords to register specific characters he does not employ the elements of "Microwriting" in which a simple down-close-on/release-off switch is crucial. If "Microwriting" were to be used on Heusinkveld's device, the device would be dropped upon release of the keys if the hand were, for example, positioned so that the palm was pointing down. Moreover, if the elements of "Microwriting" were to be employed with Heusinkveld's device using the keys as they are described, it would require two motions of each finger to register a chord, a forward motion to register a signal followed by a return motion. In Heusinkveld's patent, the independent claim, number 1, states "means for introducing several digital logic signals . . . accomplished by . . . movements of keys . . . four of said keys mounted on one side of said casing, one key mounted on the opposite side of said casing; each said key being associated with two contacts, and said keys being slide-able along the plane of the surface of the outside of the casing . . . generating a different digital logic signal at each slide position that is controlled by the tip of the each finger or the tip of the thumb." which identifies that the fingers never leave the keys. Moreover, Heusinkveld's device is neither ambidextrous nor is it able to accommodate a large variety of hand sizes since only the tips of the fingers would be useful in actuating the keys.
Another self-contained, right hand, multiple key per character, data input, storage and retrieval device has been embodied in a commercial machine known as the Agenda. The multiple key per character input scheme for a right hand, called Microwriting, is used in the Agenda and this chording scheme, as well as patent claims for the Agenda, are described by Endfield in U.S. Pat Nos. 4,443,789 and 4,360,892. The Agenda device, however, embodies a keyboard that is designed so that all keys are actuated in the same direction, namely down and away from the face of the Agenda, and therefore an auxiliary surface has to be provided for the unit to rest on, such as a desk top or another hand, in order to allow data to be entered.
The present invention is an improvement on Heusinkveld's invention as well as an improvement of the Agenda. Microwriting is, albeit limited, a market proven standard for chording which has been shown to be easy to learn, and Microwriting cannot be used on Heusinkveld's device because all the keys must be released to effect a chord and if all the buttons on Heusinkveld's device were to be released, the unit would fall from the hand.
The arrangement of buttons in the invention described here has been designed to allow single hand operation with either the left or right hand without the need for a secondary surface or another hand as Endfield's device requires. Moreover, the placement of the specific keys allows for comfortable operation of the device by a large range of left or right hands over a large variety of hand sizes and this has been done in such a way that a hand strap is not needed to hold the device. The fundamental aspects of Microwriting have been used in this invention but the similarity has only to do with the specific key combinations that are required to make specific letters and characters.
Other U.S. patents have been issued more recently which cover different implementations of single handed data entry such as U.S. Pat. No. 4,905,001 issued in 1990 to Penner in which a device remarkably similar to Heusinkveld's is described. The unique aspects of Penner's invention have to do with his devices ability to facilitate two way communication with a hand held device since the individual finger keys of Penner's device actually send tactile information back to the user based on information coming into the device. Another hand held invention was described in U.S. Pat. No. 4,998,457 by Suzuki et. al. in 1991 in which an input device for music was described. This device allows for the measurement of variable force and the translation of that variable force into differentiated music.
In 1985 Crimmins was issued U.S. Pat. No. 4,516,939 in which he described a two handed eight finger and two thumb chording device which, similar to Penner's device, gives the user tactile feedback. Crimmins uses the elements of his device as a training aid to teach people how to use his device. His device is entirely different from the device described here, but Crimmins did claim the use of his device to train people how to use that same device.
The December issue of 1992 NASA tech briefs (p15) and the Mar. 8, 1993 issue of Electronic Engineering Times (p59) describe a device called the "Data Egg" invented by Gary Friedman, Friedman's device incorporates and has reduced to practice, many of the elements of Heusinkveld's invention. He has also added the elements of Microwriting to make a single hand chording device. However, Friedman's device 1) is not ergonomically useful to a variety of hand sizes, 2) has the thumb press button on top of his device which eliminates the use of that device in many positions of the hand unless a back of the hand strap used to stabilize his device because pushing the thumb button for the space command tends to push Friedman's data Egg out of the hand, 3) does not incorporate an LCD display, although a screen is simulated with a piece of tape, and 4) it can not be used by the left or right hand interchangeably, i.e. it is not ambidextrous.
The March 1992 issue of Byte Magazine describes a hand held, single hand keyboard called the Twiddler that is manufactured by Handykey Corporation. The "Twiddler" is based on a chording scheme that was devised by Handykey Corp. and it in no way resembles "Miocrowriting" in that twelve keys are available for the fingers and six buttons are available for the thumb. There is the similarity that keys are pressed and released in chord fashion with one hand. The Twiddler is also a mouse and connects to conventional PC's through both the serial port and the Keyboard port. The Twiddler is a keyboard replacement and although it is a single hand device, it does not stand alone as a functional device and it does not incorporate any of the features of the present invention, such as the face mounted LCD, the face mounted thumb keys, five digit "Microwriting", hand size optimization, internal memory or the host of functions that accrue from the use of a stand alone self contained device like the present invention.